Jürgen Klopp is certain Liverpool could have bridged the gap at the top had players like Philippe Coutinho and Sadio Mané been fit.Photograph: Andrew Powell/Liverpool FC via Getty Images

Jürgen Klopp believes Liverpool would have competed alongside Chelsea and Tottenham Hotspur for the Premier League title but for “unlucky” injuries that stretched his resources this season.

Liverpool remain firmly on course for Champions League qualification following important victories at West Bromwich Albion and Stoke City achieved without players such as Sadio Mané, Adam Lallana and Jordan Henderson. Despite a damaging run of form in January, Klopp is adamant his team – nine points behind Chelsea, the leaders – could have sustained their early-season challenge to Antonio Conte’s side had injuries not disrupted their momentum.

“I think we can all agree that if we could have played our first 12 or 13 for the whole season, and we are only six, seven, eight points away from the very interesting region of the table, then it’s not unlikely that it could have worked,” said Klopp, whose side face Crystal Palace at Anfield on Sunday. “But it’s not important now because we don’t know for sure. It’s not allowed to look back. We have to find a lineup solution for the next game.

“What I can say is that we really need all our passion in a situation like this. I said a few days ago that it’s not about playing the best football, it’s about getting results. Most of the time it works if we’ve got a good plan but the passion is really important. We need all the passion from the stands. It’s Anfield. We’ve had two away games. It feels like we last played here eight weeks ago or something, but it was only two or three weeks. Now we are back.”

The former Wales assistant manager Raymond Verheijen rarely misses a chance to blame Liverpool injuries on Klopp’s intensive style of football and training but, as the manager pointed out, there is no set pattern to the problems that have hit his squad this season.

Klopp explained: “It’s different reasons. The problem I cannot say exactly. Look at the injuries we’ve had – not a lot of muscle injuries which is always a sign of intensity. It’s not the moment in the season where we are having the hardest training or whatever, so it’s all about individual situations. We have managed Roberto Firmino the last few weeks, kept him out of a few sessions, so it’s not that. If it happens in the game it is different. Lucas got a knock [against West Bromwich Albion], not serious, played until the end, a few problems, similar with Joël [Matip].

“That’s the situation. Adam, Daniel [Sturridge] and so on – lots of different things. Sadio and Phil [Coutinho] long-term injuries from challenges. It’s not about the day-to-day, it is just unlucky. That is the best word.”

Klopp, meanwhile, has ruled out a summer move for Manchester City’s Joe Hart and claimed he is content with his goalkeeping options at Liverpool. Hart, currently on loan at Torino, has been repeatedly linked with a transfer to Anfield but Klopp insists the England international is not an upgrade on Simon Mignolet or Loris Karius.

“We don’t usually talk about these sort of things but in this particular case I think we can,” he said of the Hart speculation. “He is a fantastic goalkeeper, the goalkeeper of the English national team, highest quality, but we have highest-quality goalkeepers. It is not for us in this moment and hopefully not for us in the future – not because of Joe but because we already have two strong goalkeepers. Wardy [Danny Ward] is at Huddersfield and playing a brilliant season. He is our player so we will bring him back next year so there is competition.”